Errors with \LTinput

[torik42]

Playing a bit around with \LTinput I noticed two things.

If one has two files, which use \LTinput to read each other, then a RecursionError: maximum recursion depth exceeded while calling a Python object occurs. As far as I understand, you check to not load packages twice, then maybe loading the same file with \LTinput twice should be prevented.

When you use \LTinput to read a file and this loaded file yields an error, e.g.

*** LaTeX error: line 2, column 1:
*** could not read file 'a.tex'

from another \LTinput, then the given position is the correct position in the loaded file. But we do not know which file this is. It would be nice if that could be added to the error message.

[matze-dd]

Thanks for these observations. :)

The first should be considered as a bug. Some time ago, I was already wondering about the second point. This would be an improvement.

[matze-dd]

Contemplating the file recursion problem, I'm wondering about the following. LaTeX macro \input repeatedly includes the files. In order to keep maximum similarities it perhaps might be better to catch the specific exception in the \LTinput macro handler and raise a better error message.

Do you have an application in mind, where we really should read a file only once?

[torik42]

I am not sure whether this applies here: Suppose I have a multi file document. Where main.tex uses \input{chapter1.tex} and chapter1.tex has \LTinput{main.tex}. Would this cause any problems? In a quick test I don’t run into recursion here. Does \input also loads \LTinput commands in the inputted file?

Otherwise, just catching the error is fine.

[matze-dd]

I am not sure whether this applies here: Suppose I have a multi file document. Where main.tex uses \input{chapter1.tex} and chapter1.tex has \LTinput{main.tex}.

Thanks for this clever case. I assume that you define, e.g., macros in the preamble in main.tex that should be available for the filter when processing chapter1.tex.

In a quick test I don’t run into recursion here. Does \input also loads \LTinput commands in the inputted file?

Macros \input and \include are ignored by the base filter yalafi. Only in a first phase, yalafi.shell goes through and collects names of files that are included by these macros. Then, each file is processed on its own using plain yalafi.

Otherwise, just catching the error is fine.

OK, then I will change it this way. Thanks for the feedback!